3 Each exposure is entered into the logistic regression model as a z-score and the outcome is binary with 1: decline and 0: no decline based on the reliable change index (RCI) criterion. RCI < -1.645 constitutes clinically significant decline between the two ARIC visits 2 and 4, which were separated by 6 years. The odds ratio is interpreted as increase in risk of cognitive decline with each 1 SD increase in the fatty acid exposure.

4 Δbias = ORnaive - ORcorrected. a: naïve estimate is biased towards the null; b: naïve estimate is biased away from the null; c: naïve estimate is biased through the null. The null value for an odds ratio is 1.00.

5 Δprecision = CLRcorrected/CLRnaive. CLR or Confidence Limit Ratio is the ratio of the upper 95% confidence limit over the lower one.